README

context: add a `blockancestors(fctx, fromline, toline)` function

This yields ancestors of `fctx` by only keeping changesets touching the file
within specified linerange = (fromline, toline).

Matching revisions are found by inspecting the result of `mdiff.allblocks()`,
filtered by `mdiff.blocksinrange()`, to find out if there are blocks of type
"!" within specified line range.

If, at some iteration, an ancestor with an empty line range is encountered,
the algorithm stops as it means that the considered block of lines actually
has been introduced in the revision of this iteration. Otherwise, we finally
yield the initial revision of the file as the block originates from it.

When a merge changeset is encountered during ancestors lookup, we consider
there's a diff in the current line range as long as there is a diff between
the merge changeset and at least one of its parents (in the current line
range).

Mercurial
=========

Mercurial is a fast, easy to use, distributed revision control tool
for software developers.

Basic install:

 $ make            # see install targets
 $ make install    # do a system-wide install
 $ hg debuginstall # sanity-check setup
 $ hg              # see help

Running without installing:

 $ make local      # build for inplace usage
 $ ./hg --version  # should show the latest version

See https://mercurial-scm.org/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.